A stent is a medical device introduced into a body lumen and is well known in the art. A stent is typically delivered in an unexpanded state to a desired location in a bodily lumen and then expanded by an internal radial force.
Stents, grafts, stent-grafts, vena cava filters, expandable frameworks, and similar implantable medical devices, collectively referred to hereinafter as stents, are radially expandable endoprostheses, which are typically intravascular implants capable of being implanted transluminally and enlarged radially after being introduced percutaneously. Stents may be implanted in a variety of bodily lumens or vessels such as within the vascular system, urinary tracts, bile ducts, fallopian tubes, coronary vessels, secondary vessels, etc. Stents can be balloon-expandable, self-expanding or a combination of self-expanding and balloon-expandable (or “hybrid expandable”).
Radial strength and opening forces are closely related to one another in stent design. In traditional stent designs, where a high radial strength is desired, a high opening force is needed. Typically where a low opening force is desired, the stent will have a low radial strength.